Enhancement of photovoltaic efficiency of phosphor doped organic solar cell by energy and electron transfer from the phosphor to C_60 acceptor

摘要

About 67% increase in power conversion efficiency (PCE) of copper phthalocyanine/C_(60) based organic solar cells was demonstrated by doping 4wt % iridium(III)bis(3-(2-benzothiazolyl)-7-(diethylamino)-2H-l-benzopyran-2-onato-N',C~4)(acetyl acetonate) (IrC_6) into C_(60) acceptor layer. The raised PCE was proved to result from the efficient photo absorption of IrC_6 followed by the energy and electron transfer from IrC_6 to C_6o due to the matched energy level alignment between these two species. Besides, IrC_6 could also increase the exciton dissociation efficiency at the active interface of the solar cells. The more detail improvement mechanisms were also discussed.